Cable sheathing machine



Feb. 25, 1941. L. R. M GUIRE CABLE SHEATHING MACHINE .F'iledAug. 30, 1937 2 Sheets-Sheet l 1941- L. R. MdGQlRE 2,233,106

CABLE SHEATHIN-G MACHINE FileiAug. so, 1957 2 Sheets-Sheet 2 Patented Feb. 25, 1941 PATENT OFFICE 2,233,106 CABLE SHEATHIl\TG MACHINE Lee Roy McGuire, Jackson Heights, N. Y., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application August30, 1937, Serial No. 161,620

14 Claims.

This invention relates to 'a machine for producing long lengths of tubing, and more particularly tubing for sheathing electrical cables, cable cores and the like. I

One of the primary objects of the invention is to produce by extrusion or otherwise, cable sheathing or tubing of considerable substantially continuous length in integral form, uniform in structure and of accurately controlled diameter.

Another object is to provide a means of produc- .ing substantially continuous tubing of considerable length for the purpose of sheathing long electrical cable cores, cables or the like with an extruded or otherwise formed and solidified tube v of material requiring high temperature for forming procedures, such as aluminum, copper, etc., in a manner whereby the low temperature combustible materials commonly used for electrical insulation will not be damaged by the high tem- 20 peratures prevailing during the sheathing procedure.

The above and other objects of the invention will be made more apparent as this description proceeds, especially when considered with the accompanying drawings wherein:

Figure 1 is a plan view partly in section of an apparatus constructed in accordance with the invention for sheathing an electrical cable;

Figure 2 a side elevation view thereof;

Figure 3 is a front end elevation view thereof;

Figure 4 is a section on the line 4-4 of Figure 1;

Figure 5 is a view similar to Figure 4 except that certain movable parts are shown in a difa ferent relation; and

Figure 6 is a fragmentary sectional view on line 6-6 of Figure 3.

Referring to Figure 1 of the several views wherein the like reference numerals refer to 40f similar parts of the embodiment here disclosed; Shaft 9 is driven by any convenient means (not shown), and H1 is a pinion driven thereby .to which is meshed gear II. On gear II is mounted y a plurality of sheath reducing members or rollers 45 I2 each paired with one of a similarplurality of radial position adjusting rollers I3 as shown in such manner on the gear II that they, are caused to revolve'about the center of and with gear- Again referring to Figure 1, the shaft 9 is sup- 1 ported by bearings 20 and has a bevel gear 2| secured to the end thereof and meshing with bevel gear for the purpose of rotating shaft 23 which extends at right.angles to shaft 9. This shaft 23 rotates two pinions 24 which mesh with 5 and rotate two gears 25 (also see Figures 2 and 3) to which are integrally fixed the crank pins 26 which rotate in the bearing bushings 21 that are secured in the respective crank pin ends of connecting rods 28. These connecting rods 28 are held in position by washers 29 and nuts 3|]. The opposite or wrist pin ends of connecting rods 28 are pivotably mountedon slidable wrist pins 3| by means of bearingbushings 32, and held ghereon by means of the washers 33 and nuts The wrist pins 3| have integral enlargements 35 thereon and are themselves a fixed part of the annular piston or plunger sleeve 36. From the descriptive details above mentioned it will be noted that the rotation of gears with their eccentrically located crank pins 26 will produce a reciprocation of connecting rods 28, wrist pins 3| and all parts attached to the latter including the plunger sleeve 36 which last is slidably mounted in a manner subsequently to be disclosed,

Referring now to Figure 4, wherein 31 is a cylinder supported by base 38 which may be located on any suitable foundation 39. This cylinder is provided with a lateral extension formed with a port 40 for the entry of hot fluid material, the extension being also formed with a flange 4| having holes 42 for bolting with the companion flange on any suitable hot fluid supply source.

At the forwardend of the cylinder 3'! is the threaded enlargement 43and engaging this is the threaded conical adjusting head 44; The inner tapered'face of head '44 contacts with the rollers l3 which are correspondingly tapered and 40 are radially movable'with supporting slide IS in the tongue and grooves machined into gear II as most clearly indicated by reference to Figure 6. By screwing the adjusting head 44 to a for-,

ward position 'on' the cylinder 31 (as shown in- 45 Figure 5) its tapering inner surface forces the rollers l3 and all parts slidably mounted therewith into closer radial relationship with the central axis of the coaxially positioned gear H and cylinder 31. It will be furtheir understood thatthe'slidably mounted "rollers I2 and I3 togetherwith their attached parts are normally held'in their outward'radialposition due to the centrifugal force resulting, from the high speed rotation of gear ll.

With further reference to Figure 4; 45 is a tapped hole in the enlarged head of the supply end of-a tubular water cooled mandrel or core guide that includes inner wall 48, water jacket space 41 and outer wall 48. This mandrel extends approximately the entire length of the machine axially of the cylinder 31 and terminates at its forward end with an externally tapering nose 49. Cooling water under pressure enters the mandrel head at tapped hole 45 from any suitable supply (not shown) and is circulated through-jacket space 41 by any suitable arrangement of forward and return passages to the outlet or tapped hole 50. By'means of the water circulated through jacket space 41 the combustible spirally wrapped paper covering or other relatively delicate insulating sheathing of the cable or cable core 5| is protected from the deteriorating effect of heat which might otherwise be transferred to it from the hot sheathing material subsequently described, the coolant also insuring a workable temperature for the reciprocating plunger sleeve 38 which is slidably positioned between the outside of mandrel wall 48 and .the inside of cylinder 31.

Also positioned in the space between the outside of mandrel wall 48 and the inside of cylinder 31 is the long tubular bushing 52 which is tightly ,fitted into cylinder 31. This bushing 52 has an inwardly tapered endslightly forward from plunger sleeve 38 when said plunger is in its-maximum forward position (Figure 4) and terminates at the right hand or front end of the machine in an enlargement 53, which enlargement acts to retain the bearing bushing 54 and hub 55 of gear II which last is rotatably mounted on bushing 52.

A relatively narrow tubular space 58 extends between the inside of bushing 52 and the exterior wall 48 of the mandrel and it is through this space that the hot sheathingmaterial is progressively moved, cooled and solidified and finally ejected by the reciprocating movements of plunger sleeve 38. During this ejective move-' ment the initially hot sheathing material loses its heat largely through its contact with man- 'drel wall 48 from which the heat is removed by solidification of the material within the spacev 58 from which it is ejected in the following manner.

A sheath forming material in fluid state as a a result of its high temperature enters the machine through the opening or port 48 which as shown in Figure 4 is closed at its bottom by the overlapping position of the reciprocating" plunger sleeve 38. As this plunger sleeve 38 is caused to move back into the position shown in Figure 5 the hot molten material passes down and into the space between the left end of the sleeve 52 and the right end of the retracted plunger and vacated by plunger 38 during its backward movement, and the fluid material.

aasame a steel tube of accurate dimensions is tightly vforced into space 58 as indicated in Figure 4 by numeral 51. The function of thisste'el tube 51 is to prevent the fluid sheathing material from flowing freely out of space 58 for reasons above stated and it also serves to correctly maintain the concentricity of the tubular mandrel wall 48 and the inner wall of bushing 52 pending the solidification of suflicient sheathing material to insure continued concentricity of these parts after the steel tube 51 has been elected from space 58 by successive forward strokes of plunger 38 through the medium of fluid pressure developed thereby.

0n starting the machine in operation, the reciprocating plunger 38 with its relatively small displacement causes a relatively high fluid pressure in the sheathing material that is trapped in space 58 between the inner end of steel bushing or tube 51 and the forward end of plunger 38 after the port 48 has become closed. It will be understood that the frictional resistance of tube 51 to election is considerable and that each successive forward stroke of plunger 38 will move form of an annulus of molten material, formed at each stroke of the annular combined ram and valve member 38, is small as compared with the progressively more and more solidified portion of the sheath extending along the mandrel and inside of the sleeve 52 is important to the satisfactory working of the invention.

After the steel tube 51 has been completely ejected from the machine by the forward advance of the sheathing material, the next step in the operation consists of screwing the conical adjusting head 44 from the position shown in Figure 4 into that position indicated by Figure 5. This adjustment has been previously described and results in an inward radial movement of rollers l2 towards cable core 5|; As the rollers [2 are caused to moveradially inward from the position shown in Figure 4 they come into contact with the solidified tube of sheathing material as it is being ejected from space 58 and the resulting contact further increases the resistance to and force required to eject the sheath material,

also the frictional contact causes the rollers H to rotate at high speed on their own axes or pins l4 (see Figure 6) in addition to their revolution as planetary units mounted on gear The inwardly radial and rotative movement of rollers I 2 against the thin solidified tube of sheathing material produces a spinning or rolling action; as a result of which the ejected sheath tube is caused to be reduced in diameter. Of course, if a spinning effect be desired, the sheath reducing members l2 will be rigid on the pins l4 instead of rotatable on these pins. The maximum inward radial position of rollers I2 is limited by contact of the end of the tapered nose 48 of the mandrel with the inner surface of the sheathing tube as shown in Figure 5.

By further reference to Figure 5, it should be noted that the tapered rollers l2 extenda small distance beyond tapered mandrel terminus 43 as a result of which it is possible to roll the sheath the herein described'invention will be apparent tube to a slightly smaller diameter than that of the minimum tapered diameter of the mandrel tapered end 49 and thus tightly envelope the cable core in a manner whereby the frictional contact between the cable core and the enveloping sheath tube will be suflicient to pull the cable core 5| through the mandrel interior at a rate of speed corresponding to. the rate of cable sheath ejection from space 56, although the advancement of the sheath tube itself, and hence of thecore with the tube may also be aided by the pull of whatever means may be used to take up the sheathed cable, or by some other pulling means, if desired.

From the foregoing, it is thought that the construction, operation and many advantages of to those persons skilled in the art to which it is related, without further description and it will be understood that various changes in position, size, shape, proportion and details of construction may be resorted to without departing from the scope of the invention and'the accompanying claims.

That which I claim is:

1. In a machine for sheathing cables, a tubu lar mandrel to receive a cable to be sheathed, means to cool the mandrel, and a cylinder coaxially surrounding the mandrel and enclosing a tubular space between the mandrel and the cylinder through which space a molten sheathmeans to cool the mandrel, and ,a-cylinder co axially surrounding the mandrel and enclosing .a tubular space between the mandrel and the cylinder through which space a molten sheathing material may be progressively moved and cooled and solidified by contact with the mandrel and cylinder surfaces prior to ejection from said space, in combination with a reciprocable annu- .lar piston positioned between the mandrel and the cylinder to. move material through the space.

3. In an apparatus for sheathing an elongated core, means to form about a core 'a sheath of greater internal \diameter than the diameter of the core, in combination with means to reduce the diameter of the sheath, which means comprises a rotatable carrier mounted to rotate about the sheath, and a plurality of tapered sheath reducing. rollers mounted on-the carrier to be revolved about the sheath by the rotation of the carrier.

4. In an apparatus for sheathing an elongated core, means to form about a core a sheath of greater internal diameter than the diameter of the core, in combination with means to reduce the diameter of the sheath, which means comprises a rotatable carrier mounted to rotate about the sheath, and a plurality of tapered sheath reducing rollers mounted on 'the carrier to be individually rotatable thereon and to be revolved about the sheath by the rotation of the carrier.

5. In an apparatus for sheathing an elongated core, means to form about a core a sheath of greater internal diameter than the diameter of the core, in combination with means to reduce the diameter of the sheath, which means comprises a rotatable carrier mounted to rotate about on the carrier radially of the sheath.

( molten sheathing material to the tubular space the sheath, a plurality of tapered sheath reducing rollers mounted on the carrier to be revolved about the sheath by the rotation of thecarrier, and means to adjust the sheath reducingrollers on the carrier radially of the sheath.

6. In an apparatus for sheathing an elongated core, means to form about a core a sheath of greater internal-diameter than the diameter of the core, in combination with means to reduce the diameter of the sheath; which means comprises a rotatable carrier mounted to rotate about the sheath, a plurality of tapered sheath reduc: ing rollers mounted on the carrier to be individually rotatable thereon and to be revolved about the sheath by the rotation of the carrier,

rollers and means to adjust the sheath reducing 7.I,In a machine for sheathing cables, a tub'ular mandrel to receive a cable to be sheathed, means to cool the mandrel, and a. cylinder coaxially surrounding the mandrel and enclosing a tubular space between" the mandrel and the cylinder through which space a molten sheathing material may be progressively moved and cooled and solidified by contact with the mandrel and cylinder surfaces prior to ejection from said space, the cylinder being formed with'a port for the entry of molten sheathing material to the tubular space, in combination with an annular piston contained in the space and reciprocable therein to advance the material therethrough and to act as a valve to control the flow of material through the port.

8. In a machine for sheathing cables, a. pair of radially spaced coaxial tubular members to receive a core coaxially therein, means to supply molten sheathing material to the tubular space between the members, and an annular piston in the space and reciprocable therein to progressively move the material therethrough while being cooled and solidified therein.

9. In a machine for sheathing, cables, a pair of radially spaced coaxial tubular members to receive a core coaxially therein, means to supply between the members, an annular piston in the space and reciprocable therein to progressively .move the material therethrough while being cooled and solidified therein, and means to cool one of the members.

10. In a machine for forming material, a pair of members defining a tubular space therebetween, means to supply molten sheathing material to the tubular space between the members, an annular piston in the space and reciprocable therein to progressively move the material therethrough while being cooled and solidified therein and to control the fiowmf material from the supply means, and means to cool one of the members.

11. Inan apparatus for forming material and having means to produce a tubular product of predetermined diameter, means to reduce the diameter of the product to another smaller predetermined value and comprising a tapering mandrel over which'the product is advanced, and a spinning roller freely rotatable on its own axis and revoluble about the axis of the mandrel in a position to run continuously on the product and thereby to spin down the product to smaller diameter as it passes over the taper of the mandrel. I

12. In an apparatus for forming material and having means to produce a tubular. product of a predetermined diameter, meansto reduce the u diameter of the product to another smaller predetermined value and comprising a tapering and means'to adjust the radial distance of the roller from the ads of the mandrel.

13. In an apparatus for forming material and having means to produce a tubular product of predetermined diameter, means to reduce the diameter of the product to another smaller predetermined value and comprising a tapering man- 'drel over which the product is advanced, a rotatable disk coaxial to the mandrel and having a central aperture through which the product passes over the mandrel, a plurality of freely 20 rotatable rollers mounted on 'the disk to be radially movable thereon and to be revolved thereby about the product to spin the same down on the tapering mandrel, and a cam member to adjustably fix the radial distance of the rollers from the axis of the mandrel.

14. In an apparatus for forming material and having means to produce a tubular product of predetermined diameter, means to reduce the diameter of the product to another smaller predetermined value and comprising a tapering mandrel over which the product is advanced, and a spinning roller freely rotatable on its own axis and revoluble about the axis of the mandrel in a position to run continuously on the product and thereby to spin down the product to smaller diameter as it passes over the taper of the man- 'drel, the roller being tapered around its periphery to correspond to the taper of the mandrel.

' LEE ROY McGUIRE. 

